Caches PhysX view's joint paths when processing fixed articulation tendons (#1347)

# Description

Cache PhysX view's DOF paths before looping when processing fixed
articulation tendons to improve loading time.

For the Shadow Hand task, calling `self.root_physx_view.dof_paths` when
iterating over all joints to find tendons attached (in
`Articulation._process_fixed_tendons` method) is an "expensive"
operation. Timing can be reduced from 2.2 seconds to 300 milliseconds
(13th Gen Intel® Core™ i9-13950HX × 32, RTX 5000) by calling
`self.root_physx_view.dof_paths` once

## Screenshots

Without any change
![Screenshot from 2024-10-28
13-30-07](https://github.com/user-attachments/assets/0bd61f3d-3013-49fb-8540-c08236b974cf)

After cache PhysX view's DOF paths before looping
(`self.root_physx_view.dof_paths` called only once)
![Screenshot from 2024-10-28
13-26-02](https://github.com/user-attachments/assets/6c2af86e-bd21-4b65-9c13-9610e6648e8d)


## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

Author: Toni-SM

source/extensions/omni.isaac.lab/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.27.9"
+version = "0.27.10"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/extensions/omni.isaac.lab/docs/CHANGELOG.rst

@@ -1,6 +1,16 @@
 Changelog
 ---------
 
+0.27.10 (2024-11-01)
+~~~~~~~~~~~~~~~~~~~~
+
+Changed
+^^^^^^^
+
+* Cached the PhysX view's joint paths before looping over them when processing fixed joint tendons
+  inside the :class:`Articulation` class. This helps improve the processing time for the tendons.
+
+
 0.27.9 (2024-11-01)
 ~~~~~~~~~~~~~~~~~~~
 

source/extensions/omni.isaac.lab/omni/isaac/lab/assets/articulation/articulation.py

@@ -1190,10 +1190,11 @@ def _process_fixed_tendons(self):
         # parse fixed tendons properties if they exist
         if self.num_fixed_tendons > 0:
             stage = stage_utils.get_current_stage()
+            joint_paths = self.root_physx_view.dof_paths[0]
 
             # iterate over all joints to find tendons attached to them
             for j in range(self.num_joints):
-                usd_joint_path = self.root_physx_view.dof_paths[0][j]
+                usd_joint_path = joint_paths[j]
                 # check whether joint has tendons - tendon name follows the joint name it is attached to
                 joint = UsdPhysics.Joint.Get(stage, usd_joint_path)
                 if joint.GetPrim().HasAPI(PhysxSchema.PhysxTendonAxisRootAPI):